Expression of a borage desaturase cDNA containing an N-terminal cytochrome b5 domain results in the accumulation of high levels of delta6-desaturated fatty acids in transgenic tobacco

Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):4211-6. doi: 10.1073/pnas.94.8.4211.

Abstract

gamma-Linolenic acid (GLA; C18:3 delta(6,9,12)) is a component of the seed oils of evening primrose (Oenothera spp.), borage (Borago officinalis L.), and some other plants. It is widely used as a dietary supplement and for treatment of various medical conditions. GLA is synthesized by a delta6-fatty acid desaturase using linoleic acid (C18:2 delta(9,12)) as a substrate. To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants. Analysis of leaf lipids from a transformed plant demonstrated the accumulation of GLA and octadecatetraenoic acid (C18:4 delta(6,9,12,15)) to levels of 13.2% and 9.6% of the total fatty acids, respectively. The borage delta6-fatty acid desaturase differs from other desaturase enzymes, characterized from higher plants previously, by the presence of an N-terminal domain related to cytochrome b5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cytochromes b5 / genetics*
  • DNA, Complementary / genetics*
  • DNA, Complementary / isolation & purification
  • Fatty Acid Desaturases / genetics*
  • Gene Expression
  • Linoleoyl-CoA Desaturase
  • Molecular Sequence Data
  • Nicotiana / genetics*
  • Plants, Genetically Modified / genetics*
  • Plants, Toxic*
  • Sequence Alignment

Substances

  • DNA, Complementary
  • Cytochromes b5
  • Fatty Acid Desaturases
  • Linoleoyl-CoA Desaturase

Associated data

  • GENBANK/AF031477
  • GENBANK/U79010
  • GENBANK/U79011